There has been proposed a related lighting control device that includes switching regulators that supply semiconductor light sources with their respective driving currents, a thermal sensor and a control means (see e.g., Document 1 (JP 2009-154748 A)).
In the lighting control device, a priority, for decreasing the respective driving currents when a temperature detected with the thermal sensor is greater than or equal to a specified temperature, is set to each semiconductor light source. When a temperature detected with the thermal sensor is greater than or equal to the specified temperature, the control means decreases the respective driving currents in order of priority (in order from a semiconductor light source with a higher priority). Here, the priorities are determined according to thermal environmental information containing information on durability and heating values of the light sources.
In the lighting control device of Document 1, since the priorities are determined according to the thermal environmental information, a rather high priority may be set to a semiconductor light source with a low heat resistance even if it is a semiconductor light source (a light source) having a high importance degree of application. In this case, when a temperature detected with the thermal sensor is greater than or equal to the specified temperature, the control means may decrease a driving current to be supplied to the semiconductor light source having a high importance degree of application and the low heat resistance in preference to a driving current to be supplied to a semiconductor light source having a low importance degree of application and a high heat resistance.